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    <title>Document</title>
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    <script>
        /* 三个数字+天
        123天
        4324254天
        */    
       var reg=/\d{3}天/g;
       var reg=/\d{3,4}天/g;
       var p="2451天地金额少了附件432天";
       console.log(p.replace(reg,"**"))   //2**地金额少了附件**

       var reg=/\d{3,4}天/g;
       var p="2451453天地金额少了附件432天";
       console.log(p.replace(reg,"**"))    //**地金额少了附件**
    </script>
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